Sixteen soldiers from the Indiana National Guard who served in Iraq have charged defense contractor KBR Inc. of knowingly letting them be exposed in Iraq to “one of the most potent carcinogens” known, according to the Boston Globe. The soldiers are requesting compensation for medical bills, payment to monitor for cancer and various health issues, and monetary damages.

The soldiers were guarding the Qarmat Ali water treatment plant that KBR was fixing following the U.S. invasion of the Iraq in 2003, and the lawsuit filed Wednesday alleges that the company knew about the harmful chemical exposure but did nothing, the Associated Press reports. They claim that the company was aware by at least May 2003 that the plant contained sodium dichromate, a carcinogen used to fight pipe corrosion, but did not alert the workers and the 139 soldiers from the Indiana Guard’s 1st Battalion, 152nd Infantry. Work continued at the plant for months afterward.

The substance also contains hexavalent chromium, which is “known to cause birth defects and cancer, particularly lung cancer,” which “can take years to develop,” according to AP.

In March, the Boston Globe reported that chromium from the plant allegedly sickened KBR civilian contract workers. At a June congressional hearing on the issue, the contractors testified that soldiers experienced similar symptoms.

“It’s not right, what they done,” said Mark McManaway, a 55-year-old truck driver and former Guardsman who is the main plaintiff in the case. He blames the chemical exposure for his nosebleeds and rashes, AP writes.

The lawsuit asserts that KBR managers initially attributed nosebleeds experienced by soldiers and workers at the plant to the dry desert weather, and work was not halted until Sept. 2003. Head attorney Michael P. Doyle said the plant opened again but workers were given protective equipment. The lawsuit also claims that some of the soldiers currently suffer from respiratory tumors linked to contact with hexavalent chromium.

KBR denies the allegations and issued a statement saying, “KBR’s commitment to the safety and security of all employees, the troops and those we serve, is the company’s top priority.”

Dr. Ken Klotz, chief of staff at the Richard L. Roudebush VA Medical Center in Indianapolis, said that no particular pattern of illness has been detected among 47 members of the Indiana National Guard who have returned from Iraq. But earlier this year, Lt. Col. James Gentry, who commanded soldiers at Qarmat Ali, was diagnosed with a rare form of lung cancer and is a nonsmoker, according to the Boston Globe. Sgt. David Moore, who was part of the same battalion and a smoker, died of interstitial lung disease in February, the newspaper reports.

KBR, based in Houston, was part of the oilfield services company Halliburton Co. until last year, when it separated from the conglomerate. Vice President Dick Cheney served as chief executive of Halliburton from 1995 to 2000.

Investigative journalist Tim Shorrock analyzed the growing amount of espionage work subcontracted by the U.S. government to private firms in his book, “Spies for Hire.” According to findingDulcinea, the book was published just months after a “procurement executive from the Office of the Director of National Intelligence gave a PowerPoint presentation at a conference in Colorado and let slip a staggering statistic”: around 70 percent of the U.S. Intelligence Community budget is allotted to private companies.

Steve Fainaru of The Washington Post, who won the Pulitzer Prize for his reports on military contracts in Iraq, reported on the fallout from a Baghdad incident in September 2007 in which Blackwater employees killed Iraqi civilians. The controversy surrounding the private security firm, allegedly “exempt” from “U.S. military regulations governing other security firms,” shed light on what Fainaru called the “uneven and largely dysfunctional regulatory system” governing private military contracts in Iraq.